The status of rapid response learning in aging

Abstract

Strong evidence exists for an age-related impairment in associative processing under intentional encoding and retrieval conditions, but the status of incidental associative processing has been less clear. In 2 experiments, we examined the effects of age on rapid response learning-the incidentally learned stimulus-response association that results in a reduction in priming when a learned response becomes inappropriate for a new task. Specifically, we tested whether priming was equivalently sensitive in both age groups to reversal of the task-specific decision cue. Experiment 1 showed that cue inversion reduced priming in both age groups with a speeded inside/outside classification task, and in Experiment 2, cue inversion eliminated priming on an associative version of this task. Thus, the ability to encode an association between a stimulus and its initial task-specific response appears to be preserved in aging. These findings provide an important example of a form of associative processing that is unimpaired in older adults.

Figure 1

Experiment 1 stimuli and design. Subjects completed two study-test blocks. Half the subjects completed the same-cue study- test block first and the remaining half began with the reverse-cue study-test block. Each block begins with the encoding task, in which subjects decide whether the presented object is typically found inside a house. An implicit test follows encoding. During the same-cue version of the test, subjects decide as quickly as possible without sacrificing accuracy whether the object is typically found inside a house. The test includes new trials and old trials from the encoding task that just preceded it. The reverse-cue study-test block begins again with encoding, which is identical to the same-cue encoding task except that a different set of trials is presented. Encoding is followed by implicit testing. During the reverse-cue version of the test, subjects decide whether the object is typically found outside a house. The test includes new trials and old trials from the encoding task that just preceded it. No objects are repeated between blocks.

Figure 2

Experiment 2 stimuli and design. Subjects completed two study-test blocks. Half the subjects completed the same-cue study- test block first and the remaining half began with the reverse-cue study-test block. Each block begins with the encoding task, in which subjects decide which of two presented objects is more likely to be found inside a house. An implicit test follows encoding. During the same-cue version of the test, subjects decide as quickly as possible, without sacrificing accuracy, which of two presented objects is more likely to be found inside a house. The test includes pairs that are new (i.e., neither object studied), intact (i.e., objects studied together during encoding), and recombined (i.e., each object studied but not together). Intact, recombined, and new status is noted above for schematic purposes but was not identified as such during the actual experiment. The reverse-cue study-test block begins with encoding, which is identical to the encoding task from the same-cue block except that a different set of trials is presented. Encoding is followed by implicit testing. During the reverse-cue version of the test, subjects are asked to decide as quickly as possible without sacrificing accuracy which of two presented objects is more likely to be found outside a house. No objects are repeated between blocks.

Figure 3

Priming effects as a function of percent change from baseline in Experiment 2. While cue reversal produced a small, nonsignificant reduction in the magnitude of item priming, it reversed the direction of associative priming, such that priming in the intact condition was no longer facilitated relative to the recombined condition. This pattern was observed in both young and older adults.